WASHINGTON (CNN) -- The United States on Wednesday joined an international treaty on adoptions -- a move that will protect both children and parents, and make the State Department a central registry tracking all adoptions coming in and out of the country, officials said.

American couple Meghan and Michael Wall hold a Guatemalan boy they are hoping to adopt.

Assistant Secretary of State for Consular Affairs Maura Harty presented the U.S. ratification of the Hague Convention on Intercountry Adoptions during a ceremony in the Netherlands.

"We would say that today is a good day for children and parents involved in intercountry adoptions," said State Department spokesman Sean McCormack.

"This convention establishes international laws and procedures for intercountry adoption. Cases involving the Hague Convention are to ensure that adoptions occur in the best interests of the children."

The agreement sets out what the State Department called "safeguards to protect the interests of children, birth parents and adoptive parents."

It says children may be adopted by prospective parents outside their country only if there is proper and informed consent from the "family of origin."

The treaty calls for authorities to make sure that birth parents haven't been persuaded to give up their children in exchange for money, urging countries to take "all appropriate measures to prevent improper financial or other gain in connection with an adoption."

Don't Miss

Officials also should make sure that the child's wishes are considered, the document says.

The treaty covers the other end of the adoption process as well, calling on the country where the adoptive parents live to "prepare a report including information about their identity, eligibility and suitability to adopt, background, family and medical history."

The rules begin governing international adoptions for the 66 signatory countries on April 1, 2008.

More than 19,000 foreign-born children were adopted by Americans in 2007 -- more than all the other countries of the world combined, McCormack said.

Final ratification "took a while" -- 14 years -- because adoption laws in the United States are generally regulated by the states, he said.

"It took quite some time to actually normalize and get a common standard among all of the 50 states and build up the right institutions and procedures so that we could comply with the convention," McCormack said.

"It took some time to do that groundwork, and when you have 50 separate sets of laws and 50 separate sets of state legislatures, it takes some time to make sure that we get it right."

Tom DiFilipo, of the Joint Council on International Children's Services, called the agreement "a great accomplishment after 14 years."

"We're just glad that it is over and will be in place in April," DiFilipo said on the telephone from Moscow, where he was giving a speech on adoption. "The basic principles, accountability, transparency, doing everything in the final interests of the child, how can you argue against that," he said.

The new rules may create delays in finalizing adoptions, especially adoptions from those countries that have also approved the Hague convention.

Guatemala, the country that provides one of the highest numbers of children coming to the United States for adoption -- more than 4,600 this year -- also just approved the international agreement, and its courts and government officials are expected to be overwhelmed.

Salome Lamarche of Families Thru International Adoption said her organization has been preparing for the new rules. Her group has handled more than 3,500 international adoptions.

She predicted significantly fewer adoptions from Guatemala, at least in the short term.

Several countries that are common points of origin for children adopted by Americans have not agreed to the treaty, including Vietnam, Russia, Ukraine and Ethiopia.E-mail to a friend